JPH01209934A - Input/output insulation type uninterruptible power source - Google Patents

Abstract

PURPOSE:To reduce the weight, size and cost of an input/output insulation type uninterruptible power source by inserting an insulating transformer having a tertiary winding between an AC output side and a load. CONSTITUTION:A transformer 11 having three windings insulated from each other is provided in such a manner that the first winding of the 3-winding transformer 11 is connected to one arm 6A of an AC switch 6, the second winding is connected to a load 9A, and the third winding is connected to the other arm 6B of the switch 6. When an uninterruptible power source 3 supplies power, insulated AC power is supplied to a load 9 through the first and second windings of the transformer 11, and when a straight forward power supply circuit 5 supplies power, an insulating AC power is supplied to the load 9 through the third and second windings. Thus, the output sides of the circuit 5 and the power source 3 as well as the load 9 are separately provided at the three insulated windings to insulate the load from the power source side and to reduce by half the total capacity of the transformer 11. Accordingly, it can reduce the size, weight and cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an uninterruptible power supply having a direct power supply circuit and having input and output insulated.

[Conventional technology]

FIG. 2 is a main circuit connection diagram showing a conventional example of an input/output isolated type uninterruptible power supply having a direct power supply circuit.

In this Figure 2, a charger 3A that converts alternating current to direct current
The uninterruptible power supply bag W13 is composed of a battery 3B for power outage backup, and a constant voltage/constant frequency inverter (hereinafter abbreviated as CVCF inverter) 3C that converts this DC to AC. After converting the AC power into AC with a predetermined voltage and frequency using the uninterruptible power supply 3,
AC power isolated from the AC power source 2 is supplied to the load 9 via one arm 6A of the AC power source 2 and an insulating transformer 7.

In order to ensure continuous power supply to the load 9 even if the uninterruptible power supply 3 trips due to overcurrent, for example, the direct power supply circuit 5 supplied with power from the AC power supply 2 can be connected to the load 9. However, in order to insulate the load 9 from this direct power supply circuit 5, a transformer 8, and to open and close this direct power supply circuit 5 and the load 9, the (lh side arm 6B of the AC switch 6) It has been inserted.

The AC switch 6 is made of Cyrisk, for example, and switches off the load by closing either the arm 6A to which the uninterruptible power supply 3 is connected or the arm 6B to which the direct power supply circuit 5 is connected. 9 can be operated continuously without power outage.

[Problem to be solved by the invention]

By the way, in an uninterruptible power supply having a direct power supply circuit 5, when it is desired to insulate the load 9 from the power supply side, as in the conventional example circuit shown in FIG. A separate insulating transformer 8 is provided for each of the power supply device 3.
and 7, and each of these transformers 7 and 8 needs to have a capacity commensurate with the load 9, so the two transformers require a large space, This has the disadvantage that the device is not only large in size but also expensive.

Therefore, the purpose of this invention is to provide an uninterruptible input/output isolated type with direct power supply circuit! 1. In addition to making the device smaller and lighter,
The goal is to reduce costs.

[Means to solve the problem]

In order to achieve the above object, the input/output isolated type uninterruptible power supply of the present invention provides insulation between the AC output side of the uninterruptible power supply having a direct power supply circuit, and between each of the direct power supply circuits and the load. In the input/output isolated type uninterruptible power supply device in which the means is inserted, an isolation transformer having a third winding is inserted between the AC output side of the uninterruptible power supply device and the load, and the direct power supply circuit is connected to this third winding.

[Effect]

This invention focuses on the fact that the uninterruptible power supply that supplies power to the load and the direct power supply circuit always supply power from only one side, and uses a common insulating transformer installed in each. By using one transformer with ζ3 windings, insulation between the load and the power source is ensured, and the device is made smaller, lighter, and lower in cost.

〔Example〕

FIG. 1 is a main circuit connection diagram showing an embodiment of the present invention.

In this Fig. 1, a charger 3A that converts alternating current to direct current
and backup battery 3B, and CVCF
An uninterruptible power supply 3 is configured with an inverter 3C, which converts AC power from an AC power supply 2 into constant voltage/constant frequency AC power, and outputs it via one arm 6A of an AC switch 6. The direct feeder circuit 5 connected to the power supply 2 outputs AC power through the other arm 6B of the AC switch 6, and the AC switch 6 equipped with two arms 6A and 6B is configured to The fact that when one arm is open, the other arm closes is the second
This is the same as the case of the conventional example circuit already described in the figure.

In the present invention, a transformer 11 having three mutually insulated windings is provided, and the first of the three-winding transformer 11: @
The wire is connected to one arm 6A of the AC switch 6, the second winding is connected to the load 9, and the third winding is connected to the other arm 6A of the AC switch 6.
Connect to B respectively.

Thus, when the uninterruptible power supply 3 supplies electric power, the power is supplied via the first @ wire and the second winding of the three-winding transformer 11.
Further, when the direct power supply circuit 5 supplies power, the insulated AC power is supplied to the load 9 via the third winding and the second winding of the three-winding transformer 11.

〔Effect of the invention〕

According to this invention, in an uninterruptible power supply having a direct power supply circuit, each winding of a three-winding transformer having three mutually insulated windings is connected to the output side of the direct power supply circuit and the direct power supply circuit. By separating the output side and load of the power outage power supply, the load is isolated from the power supply side, and the total capacity and number of transformers for this isolation can be halved compared to conventional systems, making the device smaller and lighter. This has the effect of realizing increased efficiency and cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a main circuit connection diagram showing an embodiment of the present invention, and FIG. 2 is a main circuit connection diagram showing a conventional example of an input/output isolated type uninterruptible power supply having a direct power supply circuit.

Claims (1)

[Claims] 1) In an input/output isolated type uninterruptible power supply in which insulation means is inserted between the AC output side of the uninterruptible power supply having a direct power supply circuit and each of the direct power supply circuits and the load, the uninterruptible power supply An input/output isolated type uninterruptible device characterized in that an isolation transformer having a third winding is inserted between the AC output side of the device and the load, and the direct power supply circuit is connected to the third winding. power supply.